Calculating Force of Friction on a Bicyclist

AI Thread Summary
The discussion revolves around calculating the force of friction on a bicyclist and the total force exerted by the road on the bike. A participant seeks to determine the value of the retarding force constant 'b' for a particle with a given mass and terminal speed, but their initial calculation of -4.905e-08 kg/s is deemed incorrect. Additionally, when analyzing a bicyclist traveling in a circle, the participant incorrectly assumes that the total force is simply the sum of the friction force and the normal force, leading to confusion over the correct approach. It is clarified that since force is a vector quantity, the normal force and friction cannot be directly added due to their differing directions. The discussion highlights the importance of understanding vector addition in force calculations.
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with a terminal speed of 0.2 mm/s. The particle has a mass of 10^-10 g and a retarding force of the form bv. What is the value of b? i converted everything to SI and i got -4.905e-08 kg/s but it is wrong.. am i close?

another question...

A bicyclist travels in a circle of radius 26 m at a constant speed of 7.44 m/s. The combined mass of the bicycle and rider is 95 kg.

The force of friction exerted on the bike from the road is 202 N but i need to find the total force exerted by the road on the bike. I thought it would be 202 + mg (normal force) which would be 1130. but that is not right. then i tried just normal force so i did 95 * 9.81 and i got 932. and that is wrong too!
 
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2nd part: I may be wrong here, but because force is a vector quantity, and since the normal force and friction do not act in the same direction, you cannot simply add to find the total force.
 

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